Add Heading HereI'm creating this post with the primary intent on updating the current condition of the "Mt. Jefferson Loop Trail" from Mike White's book "Backpacking Nevada"
If you are planning on following the loop as described in the book you'll start from the Pine Creek Campground and take a trail which follows a stream up towards the mountain. There will be several stream crossings which I found to be a little tricky with a full overnight pack on. The stream was flowing pretty good for mid July as there was still patches of snow higher up.
The book says at about 1.9 miles from the trailhead there is an obscure junction with a trail heading Northwest up Buck's Canyon. This faint path will ultimately provide your return to the trailhead.
My original plan was to find this path and make it my outgoing route. I kept a keen eye out for it but eventually it became apparent I had gone beyond 1.9 miles and now it was actually going to be my return route. I made summit on the South Peak and turned North on the high plateau towards my planned campsite near Barker Creek.
Quick side note: There is a junction in the "bowl" right below the South Summit where there is a wooden sign. The sign is so weathered you cannot make out what it says. The trail to the South (left) will lead you to the summit. However the trail lasts only to a small saddle before disappearing. You will have to scramble to the top however you see easiest. If you do plan to travel North along the plateau after reaching the South Summit don't make the same mistake I did. I left my heavy overnight pack at the junction in the bowl before going to the South Summit. I had to return to the bottom of the bowl and then climb back up the ridge to the North. You should take everything with you to the summit and follow the ridge north from the peak. It will save you from hiking a lot of unnecessary elevation.
Traveling along the plateau to the North there is no sign of any trail. Without a topo map it was a little difficult to pick out which valley was Barker Creek but eventually I found it. There is a faint path going from the plateau to the valley. Down in the Barker Creek valley I set up my tent in the grass. There is flowing water but a LOT of cow pies. I wouldn't drink straight from the creek. Also the bugs were heavy in this valley.
The second day I climbed back to the high plateau and climbed to the East up a moderately steep section before turning North following the ridge. Again, there isn't any kind of trail along the ridge so it's a good idea to have a topo map. I continued past North Peak along the ridge until I came to a gentler sloping bowl to the east side of the ridge. This bowl will be the first place you come across with any kind of achievable decent. I scrambled down the bowl into the trees and along a flowing creek.
The "Backpacking Nevada" book will tell you that there is a faint trail to be found once in the valley. I was unable to find any sign of anything and decided to follow the creek back down. Following close to the creek was nearly impossible with many down trees blocking the way and heavy undergrowth. I hiked a little higher up where the vegetation was more manageable but kept the creek to my left within ear shot. The majority of my hike from here was absolute hell. I was mostly bushwhacking with the exception of short "game trails" which were made from cattle which graze the area. I followed one of the more distinct "game trails" which lead me onto a treeless ridge where I could plan out the rest of my decent. There was a fork ahead of me with two streams coming together. I hiked down to the right and again followed the water. It was at this point where the stream gained some size but the canyon walls to both sides were very steep. The only way to travel this section was in the lowest part of the valley where the thorns and trees were the thickest. I made several stream crossings where the foliage growth forced me to find an other way. This went on for about 2 miles, my arms and legs itchy and bleeding from the thorns. At some point I was able to distinguish a hiking trail. Some of the down trees had been sawed along the trail but more recently fallen trees still blocked the way. Even though a trail was discernible the thorns and down trees were still a impeding force. It wasn't until the last 1/4 mile that the trail opened up to a usable route. The last section of the trail made one more difficult stream crossing and disappeared just within sight of the main Pine Creek trail. When I stood back on the main trail I tried to find any markings to show the junction but there was absolutely no indication that a trail was ever there.